The present invention relates to a laser cutting tool. In particular, the present invention relates to an apparatus for selectively directing cutting debris away from a preferred portion of a workpiece so that the cutting debris does not settle thereon.
Laser beams are used in numerous applications, including drilling, machining, scribing and cutting a variety of different materials. While using a laser beam in these types of applications, it is typical that cutting debris or smoke from the lasered material becomes airborne. These particles either immediately settle or suspend in the air for a period of time until they either settle upon the workpiece or elsewhere. In most circumstances, it is desirable that the particles do not settle upon the workpiece. An example of this would include the use of optically clear plastics.
When laser beams are used for cutting optically clear plastics, the laser beam typically cuts the workpiece into a preferred portion and a scrap portion. In this situation, it is important that the cutting debris be kept away from the preferred portion in order to keep the entire surface of the plastic workpiece optically clear. It is less important, if at all, as to what settles upon the scrap portion, which is either discarded or recycled for other uses.
In the event that cutting debris deposits upon the preferred portion, that portion must then be washed to remove the cutting debris, thus ensuring that the plastic is optically clear. This is burdensome and causes an additional cost to manufacturing. One way to ensure that cutting debris is not deposited upon the preferred portion of the optically clear workpiece is to place a cover sheet upon the entire workpiece. The laser beam cuts both the cover sheet and the workpiece at the same time, with the cutting debris settling upon the cover sheet. Upon completing the cutting process, the cover sheet is removed from the preferred portion of the workpiece, and then discarded. This is also burdensome and wasteful, with the cover sheet being an added expense that must be discarded after its use.
Thus, it is preferable to direct the cutting debris created by the laser beam from settling upon the preferred portion of the optically clear workpiece. There exists in the art stationary suction or blowing devices which achieve this purpose. However, these devices are somewhat limited to the application of either straight-line or purely radial cuts. These devices are not very effective when a multi-directional cut on a single workpiece is desired. As used herein, multidirectional cuts means a pattern of the preferred portion having an edge or line changing direction such as at a corner, a curve with either an increasing or decreasing radius, a curve having an inflection point, or any combination thereof. The positioning of the stationary blower and/or suction device tends to direct some or all of the cutting debris in a single direction. When a laser beam makes a multidirectional cut in relation to the workpiece, the direction that the cutting particles must be directed in order to resist deposition upon the preferred portion of the workpiece must change with the direction of the cutting path.
The present invention is an apparatus which selectively positions a nozzle to pneumatically direct cutting debris away from a preferred portion of a workpiece wherein a laser beam separates the workpiece in a multi-directional relation. The apparatus comprises a member positionable about a laser beam cutting device, the nozzle attachable to the positionable member, and a programmable logic controller to selectively position the positionable member and nozzle.